The images, shown below, were published on a Japanese website weekly.ascii.jp. Apple is reportedly going to launch its next-generation iPhone on Sept. 10, along with a low-cost smartphone rumored to be called the iPhone C. The Cupertino, Calif.-based company, however, has not yet confirmed an official release date or a cheaper iPhone model.

(Read more: Apple expected to show next iPhone on Sept. 10)

Rumors of a gold iPhone have circulated for a while now, but TechCrunch reported last week that a gold or champagne color would be coming out this year.

Charles Golvin, a principal analyst at Forrester Research, told CNBC earlier this week that while he is not sure Apple will roll out a gold iPhone, the company will eventually have to begin to include color into its iPhone line.

"It's not a matter of if Apple will add more colors, but it's really a matter of when ... and what is that color going to be," Golvin said. "If you look at the competition and what they are offering, it's reasonable to say that Apple has reached the end of the line of just offering black and white."